This Rapid application proposes to conduct a randomized controlled trial with 42 male or female New York City disaster relief workers exposed to the terrorist attack of September 11, 2001 and its aftermath who carry a primary diagnosis of full or subthreshold PTSD related to the event. One hundred and five workers will be included in the initial assessment for DSM-IV Axis I disorders and PTSD symptom status to allow for a 20 percent non-inclusion and 30 percent dropout rate. Subjects meeting inclusion criteria will be randomized to either a 5-session CBT treatment (CBT; N= 21) or treatment as usual condition (TAU; N= 21). The sites for treatment will be the New York Weill Medical Center of Cornell University, Manhattan and Westchester Campuses. Treatment adherence will be assessed by the study team utilizing instruments developed by the authors of the manual, modified for use with disaster relief workers. Participants assigned to the CBT condition will complete self-report questionnaires at the end of each session. Post-treatment clinical interviews will be administered after the completion of the 5-week trial, and self-report assessments will be administered post-treatment and at 3 months. The aims of this proposed study are: (1) to evaluate the efficacy of a 5 session manualized individual, cognitive behavioral treatment (CBT), adapted for use with disaster workers, compared to a treatment as usual (TAU) contrast group; (2) to prepare for a larger scale three group randomized controlled study of CBT, EMDR, and supportive counseling for emergency services personnel exposed to a variety of critical incidents; (3) to explore potential moderators of treatment response in the CBT group, including baseline anger, reports of dissociation during trauma exposure, and dissociation during prolonged imaginal exposure in treatment.